Calculate the ÄHvap , in kJ/mol, for ethanol, given that the vapor pressure at 45.0°C is 155.0 torr. The normal boiling point of ethanol is 78°C. Express your answer to two decimal places.

Answer 1

Use the Clausius-Clapeyron equation.
p1 = 155 torr
T1 = 45.0C
p2 = 760 torr
T2 = 78 C
change dHvap to J/mol